Blacking for heated iron.



GEORGE H. .TQHNSON, OF PAXTON, MASSACHUSETTS.

BLACKING FOB HEATED IRQN.

Application filed Becembcr Zfi, 1987.

T 0 all whom it may concern:

Be it known that l, Gnonsn H. JoHNsoN,

a. citizen of the United States, residing atch is but is merely rubbed on the surfaceoi' thesame so that it will present a black surface for a limited period oi time. The graphite is usually put up with a binder or the like which is decomposed by heat so that after the hlocking or dressing is applied it i *ill become loosened and disappear in a short time after the stove or other article on Which it is used is heated to the ordinary temperatures to which stoves and the like are subjected The principal ourpose of this invention is to provide blaclring or dressing Which is so affected by the ordinary heating of a stove or the like that when applied to the iron it Will iroduce a coating intimately united with the surface of the. iron Without the interposition of any bind er or the like. In this Way, a surface is secured which will only be more permanently lined by heating and cannot be removed in the ordinary use of the stove except by the repeated rubbing of metal surfaces against the iron. in order to accomplish this result, the iron is dressed with a metallic salt in solution either in com. bin-anon with other substances or not, saidsalt being of such that re that a black metallic oxid having a metallic luster will be fixed to the surface of the iron when the stove, is heated. Preferably also a metallic salt is used which is of such a nature that the desired result may be securedin two ways; first simply by decomposing the salt When the stove is heated to produce the black oxid; and second, by precipitating a metal from the salt upon its contact With the iron cold state and leaving the metal taly united with the surface of the in such condition' that When the black mid will be formed ml with the iron as in the Specification of Letters Patent.

Patented May is, race.

Serial No. $08,188:

other case. in all cases, the black oyid is in contact the iron wnou in stem ncsccndi, so that it unites the 'h and thus produo-es a result not attained lay simply coating the iron with the hlaclr. oxio'. in suspension in a liquid, orsnixed in a paste.

As aspeciiic example of practicable Way of carrying out the invention, cupric hydroXid is dissolved, preferably in ammonia water, and applied to the surface of the iron. ..t is Well known that this liydroxid possesses the property of losing its Water when heated, even when underwater l changed to black cupric oxid; consequently, it it'is ap- LO a hot stove the result will he the production of a surface of cupric oiiid on the iron and as this surface is formed in a chemical manner While in contact with the iron which is in a heated condition, it has been found in practice that it is firmly united With the iron. and can'only lie-removed by slow degrees in the ordinary use of stove. Obviously, any further heating of the stove has no effect on it after it is once fixed unless it be to more firmly fix it in position. Consequently, the coating is excedingly durable in practice and will be removed only in the course of time by theconstant attrition which it re ceives by the use of utensils ordinarily ern ployed on stoves. Another important advantage of this method of carrying out the invention is that the cupric 01nd has a mejtallic luster and that it is composed of a black, amorphous powder which at high temperatures settles together so as to form a hard coating, which can be blacked over with ordinary forms of blaclring so as to receive a high polish therefrom. ltis referred also to place a black fillerot any kind, as for example. tannate of iron, in the solution in any desired proportion but preferably cniantity. This especially when used with the nitrate solution .rnentioned hereinafter gives the composition a body and, serves to give a smoother surface torough iron.

in a small also by means of its color makes it look like an ordinary blacking and has no dole terious effect on the ar icle when used for the purpose for which it is intended. Another salt which can be used is the basic copper carbonate. The eupric nitrate also may he used as it is easily converted by heat into blacli cupric oXid and as it is readily soluble inwvater alcohol. ii'hon dissolved in Water for this pin'pose, it is preferred to I for commercial purposes.

heat the solution almost to .the boiling oint and then allow it to cool. It has been ound in practice that while this action. does not 1 when broupht into contact with the iron in a cold'state; caving the cop er united with the surface of the iron in 'suc h form that black oxid will be produced when it is heated'afterwards. nitrate should be slightly acid, and may contain free nitric acid.

I am aware that the materials used and the method of carrying out the invention may be varied by a skilled chemist without departing I) claim 1s:

temperature, as

When the tannate of iron is used the from the scope of the invention as expressed in the claims.

Having thus described my inventiqny jwhat 1. A blackin comprising a solution of a copper salt capable of being decomposed by heat to produce black on )ric' oxid.

2. A b aching or witnesses.

, GEORGE H; JOHNSON, WVitnesses:

A. E. FAY, C. FLWESSON.

or dressing for iron surfaces I dressing composition for non surfaces comprising a black filler, and a 

